Unified junior welterweight world champion Terence Crawford is widely considered one of the best pound-for-pound fighters in the world. At age 29, he is in his prime and has won world titles in two weight classes -- lightweight and junior welterweight -- and unified two of the 140-pound belts. He also was the consensus 2014 fighter of the year.

Terence Crawford vs. Felix Diaz

Last July, he beat down Viktor Postol, the No. 2 fighter in the junior welterweight division at the time, to unify the belts in a virtuoso performance in which he dropped Postol twice and cruised to a lopsided unanimous decision. It was the best victory of his fine career.

Crawford's next fight was a mismatch on paper and turned out that way in the ring in December when he ran roughshod over John Molina Jr. in an eighth-round knockout victory that was not competitive for a single moment.

But now Crawford, making his fifth title defense, steps back up to face a strong contender in Felix Diaz, a 2008 Olympic gold medalist from the Dominican Republic, when they square off on Saturday (HBO, 10:15 p.m. ET/PT) on the big stage of famed Madison Square Garden in New York.

In a notable co-feature, lightweights Raymundo Beltran (32-7-1, 20 KOs), a 35-year-old Mexico native fighting out of Phoenix, who has had two unsuccessful world title bids, and Jonathan Maicelo (25-2, 12 KOs), 33, a Peru native fighting out of North Bergen, New Jersey, will meet in a world title eliminator that will put the winner in position for a mandatory shot against titleholder Robert Easter Jr.

The remainder of the undercard, which Top Rank will stream live at TopRank.tv beginning at 6:35 p.m. ET, will feature an array of talented fighters, including three 2016 Olympians who rate as blue-chip prospects: featherweight Shakur Stevenson (1-0, 0 KOs), a U.S. silver medalist from Newark, New Jersey; junior welterweight Fazliddin Gaibnazarov (1-0, 1 KO), a gold medalist from Uzbekistan; and lightweight Teofimo Lopez Jr. (4-0, 4 KOs), who is from Davie, Florida, but represented his parents home country of Honduras at the Rio de Janeiro Games.

Terence Crawford (30-0, 21 KOs) vs. Felix Diaz Jr. (19-1, 9 KOs)

What's at stake

Crawford, the pride of Omaha, Nebraska, is putting his two world title belts on the line against Diaz, not to mention his undefeated record and his place on the pound-for-pound list. Virtually all outlets that compile P4P rankings have Crawford in the top 10. The ESPN.com panel ranks him sixth.

But Crawford is a fearless fighter and has never been one to shy away from a challenge, and he's not about to start. Diaz is a highly regarded contender whose only loss came via controversial majority decision in 2015 to Lamont Peterson, a former junior welterweight titlist who now owns a secondary welterweight belt.

Many hope that Diaz's skill set and tenacity will bring out the best in Crawford and present him with the kind of legitimate challenge Postol, Molina and others did not.

"We shall see," Crawford said. "A lot of people look at the fights and ask who will bring out the best in Terence Crawford, who is going to bring out this in Terence Crawford -- we want to see Terence Crawford in these types of fights. But again, I make my adjustments and it's just that. So we are going to have to see how the fight is going to go or what is going to happen. I just fight the fight."

Since the loss to Peterson, Diaz has won two fights in a row, including an impressive unanimous decision win against then-undefeated rising welterweight contender Sammy Vazquez last July. A win over Crawford would be huge.

"I'm up for this challenge," Diaz said. "I really believe this will be a war on Saturday night. I'm going to have massive support from my fellow Dominicans. I have a great chance of winning this fight. I see a lot of weaknesses in his game that I know I can take advantage of. He is one of the best, but I have fought at welterweight and he hasn't. I believe I have the power to hurt him."

Calling Crawford

Diaz and promoter Lou DiBella have spent the past year calling Crawford out. Since Diaz beat Vazquez, this is the fight Diaz has pressed for. He hoped to land the fight at the end of last year, but Top Rank matched Crawford with Molina instead.

But, finally, with no other reasonable available opponent for this weekend's HBO date, Diaz got the call.

Felix Diaz, right, is fighting for a world title for the first time in his career. David A. Smith/Getty Images

"When you are at the top of the division, everyone wants to fight the guy at the top, especially when they can get their name out there to boost their ratings. I didn't take it as nothing, really," Crawford said of being pursued so heavily by Diaz and DiBella. "I never ran away from any challenge. He's got the skills, he's a good fighter, he is an Olympic gold medalist and this is the fight that a lot of people were calling for, and we are here now."

Said Brian McIntyre, Crawford's trainer and co-manager: "We were never running from Diaz. We just got this opportunity to do this. So here we are. Team Diaz, you are going to get what you have been wishing for and it's not going to feel good."

Top Rank chairman Bob Arum was at first lukewarm to matching Crawford with Diaz last year but eventually came around and was able to make a deal with DiBella.

"Felix Diaz in an Olympic gold medalist and that means something," Arum said. "A gold medalist has a lot of confidence and a lot of credentials and ability. I am delighted that he stepped up to the plate. His promoter, Lou DiBella, was very helpful in making the fight and very cooperative.

"It is going to be a terrific fight for the fans, and Terence only wants to fight the best. Whoever is the best that steps up is the one Terence is going to fight. Terence has never ducked anybody. The whole time he has been with Top Rank he has never ducked an opponent. It's not a question of matching him correctly. It's not a question of being cautious. Terence will fight anybody who steps up to the plate."

Diaz, a 33-year-old southpaw, said he called out Crawford for one specific reason.

"I called out Terence because Terence is the best in the division," he said. "It is a big opportunity for me to fight at Madison Square Garden against Terence Crawford. With his style, I know I can beat Terence Crawford. Crawford has fought no one like me. Stylistically, I can beat him."

Asked if Crawford was perhaps a bit overrated, DiBella pondered the question for a moment.

"I think he is a damn good fighter," he said. "Do I think he is overrated? I think he has fought some smaller guys. I don't think his resume screams of the best in the world, but in this day and age not a lot of resumes do. Until someone proves otherwise, he is a terrific fighter and Felix wanted this fight because he views Crawford as the best. I do believe that now he will be in there with a guy with real credentials who is a real 140-pounder. He has maybe fought a lot of guys that were smaller and not at the level of Felix. But I take nothing away from the guy -- he is certainly one of the top pound-for-pound fighters in the game today.

"Unfortunately we don't have a lot of resumes that look like [Thomas] Hearns, [Sugar Ray] Leonard, [Roberto] Duran, [Pernell] Whitaker or those kinds of situations anymore because we have to do a better job of getting the best in with the best. This is an example of the best fighting the best."

The grand stage of Madison Square Garden

In February 2016, Crawford made his New York debut with a fifth-round knockout of Hank Lundy in a title defense at the Theater at Madison Square Garden. But now he is moving into the main arena to fight for the first time and that's a big deal for any fighter.

"I'm excited to be fighting in the Garden's main arena and following in the steps of great fighters -- legends," Crawford said. "I am proud to continue the tradition. I don't feel any pressure fighting at the Garden. The ring, no matter where it is, always feels like home to me. I just have to keep winning.

"If I keep winning, then the opportunities for even bigger fights will present themselves. But this is a really big fight to me. Diaz is a worthy challenger and you can't bring just any fight to the Garden. I didn't get this far without winning. I'm ready for any opportunities at 140 or 147 pounds. I want to put a show on for everyone on Saturday night. I will make a statement.

"For me, going from the Theater to the big arena right now -- that says a lot right now."

Diaz is also amped up to fight at MSG for the first time.

"It is great to be able to fight at Madison Square Garden, the mecca of Boxing and the mecca of history," he said. "I know that a lot of the Dominicans from Manhattan and the Bronx and the Dominican communities will be coming out to support me."

Arum has promoted many major fights in the Garden's main arena and said he was pleased to add Crawford to the list.

"Obviously fighting in the main arena as the main event makes a statement and it's what our plans are, and our plans are that Terence Crawford, before he hangs up his gloves, will be recognized as the greatest fighter of his time," Arum said. "That's going to be up to Terence, but he has the tools, the personality and the ability to reach that goal. And our job as a promoter is that he has every opportunity to show the world that he is the best fighter of his era.

"Fighting on the big stage that is Madison Square Garden where [Muhammad] Ali fought and where Marvin Hagler fought, where Oscar De La Hoya fought and now where Terence Crawford is fighting, is a step in that direction. Obviously, we could have taken the fight to Omaha and have a massive sellout like we always do, but we decided that we wanted to showcase Terence at the 'Mecca of Boxing,' Madison Square Garden.

"There is no place else in boxing, with all due respect to Las Vegas and other arenas, there is no place in boxing that has the symbolism and the history of Madison Square Garden. Now Terence will have the opportunity to perform on the biggest of all stages."